Amelie Mauresmo with the WTA Championships trophy in Los Angeles on Sunday. (Reuters)

Los Angeles: Amelie Mauresmo rallied from a set down to outlast compatriot Mary Pierce 5-7, 7-6, 6-4 in the WTA Championships final on Sunday, making her the first Frenchwoman to win the season-ending tournament.

In a compelling contest that spanned three hours and six minutes, the tireless Mauresmo’s brilliant defence and athleticism carried her to the biggest title of her career in her second appearance in the final of the eight-woman event.

“It’s great,” Mauresmo said. “So many people said I couldn’t win. I’m so glad I went through this moment. Hopefully there will be many more like this.”

Considered one of the Tour’s most talented players never to have won a Grand Slam title, the 26-year-old fourth seed proved she had the credentials to triumph at the highest level by capping a week of solid tennis with a gritty victory in the final.

“You have some ups and downs,” Mauresmo added. “You have moments when you believe that it is going to happen and some moments when your mind is down a little. You think to yourself, ‘I’m never going to do it.’ But most of the time I’ve been very positive about it.”

The Fed Cup teammates traded early breaks in the first set before the 30-year-old Pierce gained a vital 6-5 lead when Mauresmo erred on a forehand. Piece was able to serve out the set when Mauresmo missed another forehand.

Undaunted by the loss of the opener, Mauresmo broke early in the second set to build a 3-1 advantage but paid for another forehand error three games later to allow Pierce to pull back to 4-3.

Mauresmo regained her composure in the tie-breaker as Pierce struggled with her focus and was able to secure the set by a 7-3 margin with a stunning backhand crosscourt winner.

The two traded early breaks in the deciding set, but it was clear that Mauresmo was getting the better of their longer rallies.

When the tiring Pierce missed an easy forehand to hand her opponent a crucial break in the ninth game, Mauresmo appeared well set to serve out the contest.

However, Mauresmo quickly fell to 0-40 before Pierce collapsed completely, committing six straight unforced errors to hand her opponent the victory.

Mauresmo then fell to her knees, lifted her arms to the sky and went up into the stands to hug her coach, Loic Courteau.

“Court coverage was key,” said Mauresmo, who committed only 25 unforced errors in the match to 44 from Pierce.

“I didn’t want the rallies to last one of two shots. I wanted to make her work and that’s what I did from the beginning. That paid off in the third set.”

With the victory, Mauresmo moves up a spot to No. 3 in the rankings released on Monday.

“I really feel like this is a huge step for me,” Mauresmo said. “I don’t know where it is going to take me but it’s a step and usually when you pass something like that, you realise that. It’s an important moment and really great what I’ve achieved.”

Pierce will end her productive year ranked No. 5.

“Any loss is tough, especially in a close match where you feel like you had opportunities,” said Pierce, who converted only four of her 16 break points chances.

“I did everything in my power that I could do, but I could have played better.”